Have a 3G iPhone. The battery wasn't holding a charge, so I decided to try another phone on AT&T - not really happy with it so want to go back to iPhone. I took to a mac repair store and they changed out the battery. The battery works great and it connects to my home network (which is working), but I can't seem to get it to run off wifi. No service plus wifi doesn't seem to work. Still have the SIM card. Have tried resetting phone, network, network settings, running in airplane mode, etc - nothing seems to work. It seems to get a full signal on the network, but it won't actually pull in data (load pages, etc.). I want to make sure the wifi is working properly before I go through the trouble of having AT&T reactivate the phone. Any suggestions?